Can I ask What is relationship Between PCN Restriction & Regulated Takeoff weight Of An aircraft
I have an amateur interests in these issues and will try to give an answer to your question but there are experts in this forum, such as OverRun, who will be able to correct any misconceptions that I may have and fill in any gaps.
Many factors affect the permissible take-off weight of an aircraft from an airfield. These include;
The ACN of the aircraft. For a brief explanation of ACN, see
Aircraft classification number - Wikipedia, the free encyclopedia
The PCN of all the pavements that the aircraft will use for parking, taxiing and take-off. For a brief explanation of PCN, see
Pavement classification number - Wikipedia, the free encyclopedia
The performance of the aircraft, including any self-imposed restrictions such as de-rated engine performance (often used to to extend engine life) or any serviceability issues. Some quite detailed aircraft performance data is available on the Boeing and Airbus web sites e.g.
Boeing: Airport Technology
Aircraft Characteristics *| Airbus, a leading aircraft manufacturer
The prevailing weather conditions; low air pressure (as a result of altitude and/or low atmospheric pressure) reduces engine performance as does high ambient temperatures. Wind conditions (direction, strength and gusts) and the available friction on the runway also need to be taken into account. e.g. a wet runway increases stopping distances in the event of a rejected take-off.
The runway length, runway surface (e.g. ice, asphalt, concrete, gravel, grass) and surface condition (wet, dry, snow, ice, other contaminants, degradation).
Airfield operator, aircraft operator and regulatory restrictions. e.g. some airfields have noise restrictions that might affect take-off performance of some aircraft and some aircraft operators have policies that require reduced engine performance to be used in order to extend engine life and times between overhauls. Also, some airfields might allow some aircraft types to operate regularly at an ACN that exceeds the PCN of a pavement. A 10% overload is often permitted on a regular basis and for occasional operations higher overloads might be permitted, subject to regular inspections of the pavement by suitably qualified engineers. Here is an example of the data that is published by an airfield operator and by a regulator;
NATS | AIS - Home (see the "Textual Data" link)
http://www.caa.co.uk/docs/33/CAP168.PDF
In order to calculate the weight that any particular aircraft can depart at from any particular airfield, all of these factors, and probably some others, need to be taken into account.
If we take Edinburgh Airport as an example, let's look at the effect that PCNs can have on the maximum permissible take-off weight for a Boeing 777-300ER.
Currently, the only stand that is capable of accommodating an aircraft of this size has a PCN of 72/R/C/W/T. Until last year, the main runway had a PCN of 74/R/C/W/T but, at that time, the apron and runway were connected by a relatively short section of taxiway (taxiway Mike) which had a PCN of 31/F/C/X/T and another taxiway (taxiway Alpha) that had a PCN of 72/R/C/W/T. For this aircraft type at that airfield at that time, the biggest constraint on take-off weight was not the runway length but the PCN (strength) of taxiway Mike.
At the time that Edinburgh Airport was bought by new owners last year, the PCN of taxiway Mike was re-assessed as having a PCN of 37/F/A/W/T. Some time later Taxiway Alpha was re-assessed as being 70/F/A/W/T. and the main runway has since re-assessed as having a PCN of 87/R/C/W/T. The limiting factor for take-off weight for a Boeing 777-300ER remains taxiway Mike with a PCN of 37/F/A/W/T, albeit, the A-strength sub-grade allows a significant increase in the permissible weight of a Boeing 777-300ER.
Taxiway Mike had some significant works carried out on it earlier this year but the PCN has not been revised yet. I am assuming that the airfield owner is allowing the surface to bed down before carrying out a technical re-assessment of its PCN but I cannot say for sure whther this is the case. If, by way of example, a re-assessment in the coming months increases the PCN of taxiway Mike to, let's say, 70/F/A/W/T then the limiting factor for Boeing 777-300ER operations at Edinburgh would be the PCN of the apron where the aircraft parks which is currently 72/R/C/W/T.
If that apron is re-assessed / refurbished and attains a PCN of, let's say, 70/F/A/W/T (this is the PCN that Taxiway Alpha attained after it was re-surfaced and re-assessed) then the limiting factor for Boeing 777-300ER operations would become the runway length and/or weather conditions.
As you will see, aircraft take-off weight at any particular airfield is a complex subject and requires careful calculations by suitably qualified people. As I said at the start of the the thread, I am a self confessed amateur but if you read some of the information in the links that I have provided you will hopefully get an initial understanding of this complex subject.